Fam-Trastuzumab Deruxtecan-Nxki (TDxD)

This is Phase 1 dose finding trial with potential dose expansion to evaluate the safety, toxicity, recommended phase 2 dose (RP2D), and maximum tolerated dose (MTD) of Neratinib plus TDxD using a standard 3+3 dose escalation design in patients with metastatic or unresectable gastro-esophageal cancer that are HER2-overexpressing (IHC 3+ or IHC2+/ISH+) and any other gastrointestinal cancer with HER2 expression with IHC3+. Patients must have progressed or been intolerant of at least one prior line of chemotherapy + HER2 directed therapy.

The purpose of the study is to learn from the real world practice of prescribing targeted therapies to patients with advanced cancer whose tumor harbors a genomic variant known to be a drug target or to predict sensitivity to a drug. NOTE: Due to character limits, the arms section does NOT include all TAPUR Study relevant biomarkers. For additional information, contact TAPUR@asco.org, or if a patient, your nearest participating TAPUR site (see participating centers). \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* Results in publication or poster presentation format are posted as they become available for individual cohorts at www.tapur.org/news. The results may be accessed at any time. All results will be made available on clinicaltrials.gov at the end of the study. Indexing of available results on PubMed is in progress. \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*